Each of the little numbers has a lot of tradition. Please consider that even when some units are 12-based, they still are embedded within the 10 (0-9)- based number system, even in Anglo-American-tradition countries. The Romans had a (non-)system which must have been a pain for every bookmaker. Some authors I've read claim that the 10-based number system is not accidental, but holds a deeper truth. Mathematically it doesnt matter in which system we encode the quantity of elements of a set. But the cardinal numbers of course have different mathematical properties, such as being a prime number and such. A mathematician might tell you the specifics of the cardinal number 12.

Spooky